The purpose of the project is to develop a robotic exoskeleton for clinical rehabilitation of upper extremity movement. The project has three main goals. First, the robot will provide movement training for key motions such as: wrist supination, wrist extension, shoulder external rotation and hand opening. The investigators will solve the technical issues by adding more degrees of freedom to the robot while keeping it light-weight, powerful, and safe by building on advances in pneumatic control, and altering the underlying geometric structure of the robotic exoskeleton. The second goal is to maximize the capability of the robotic device to provoke plasticity by improving the high-level control software that dictates how the robot assists movement. The third goal is to test the hypothesis that inclusion of more naturalistic movements and optimal assistance during robotic rehabilitation therapy improves motor outcomes following stroke.